
Some treatment plants follow this with a sand filter, to remove additional pollutants. The water is then disinfected with chlorine, ozone, or ultraviolet light, and then discharged. For more information about any of the steps of the water treatment process, see the Chlorination fact sheet.
What is the purpose of a wastewater treatment plant?
Wastewater Treatment Plants. Wastewater treatment facilities in the United States process approximately 34 billion gallons of wastewater every day. Wastewater contains nitrogen and phosphorus from human waste, food and certain soaps and detergents. Once the water is cleaned to standards set and monitored by state and federal officials,...
What are the steps in the water treatment process?
The water treatment process to deliver safe and wholesome water to customers includes many steps. Coagulation, flocculation, sedimentation, filtration, and disinfection are the water treatment processes that make up a conventional surface water treatment plant.
What is a conventional surface water treatment plant?
Coagulation, flocculation, sedimentation, filtration, and disinfection are the water treatment processes that make up a conventional surface water treatment plant. These water treatment processes ensure that the water consumers receive is safe to drink and aesthetically pleasing.
How do wastewater treatment plants pollute the environment?
Wastewater Treatment Plants. Wastewater treatment plants process water from homes and businesses, which contains nitrogen and phosphorus from human waste, food and certain soaps and detergents. Septic systems can easily become a source of nutrient pollution if not properly maintained.

What steps are taken to clean the water at the water treatment plant?
There are chemicals added to the water as it enters the various treatment processes.Step 1 Chemical Coagulation. ... Step 2 Flocculation. ... Step 3 Sedimentation. ... Step 4 Disinfection. ... Step 5 Filtration.
Where does the water treatment plant send the clean water?
What happens to the treated water when it leaves the wastewater treatment plant? The treated wastewater is released into local waterways where it's used again for any number of purposes, such as supplying drinking water, irrigating crops, and sustaining aquatic life.
How is water cleaned in a sewage treatment plant?
The wastewater enters an aeration tank, where it is mixed with sludge. Air is then pumped into the aeration tank to facilitate the growth of bacteria and other small organisms within the sludge. The bacteria and other microorganisms break down the organic matter in the water into harmless byproducts.
What are the 4 steps of water purification?
4 Steps of Community Water TreatmentCoagulation and Flocculation. ... Sedimentation. ... Filtration. ... Disinfection.
How is water cleaned?
During filtration, the clear water passes through filters that have different pore sizes and are made of different materials (such as sand, gravel, and charcoal). These filters remove dissolved particles and germs, such as dust, chemicals, parasites, bacteria, and viruses.
What happens to poop at the water treatment plant?
During the first stage, all of the waste that accumulates in the city's pipes just sits in a tank for hours. This stage allows the solids to settle at the bottom of the tank. The water at the top of the tank is skimmed off and sent off to be processed. Your poop remains in the sludge that's left over.
How do you purify water drainage at home?
Inspection chamber/ Grease trap. Pipes carrying greywater from multiple sources (bath, washing machine etc) in the house, bring the water to inspection chamber. ... Baffle filter. Baffle filter comprises a filter and multiple baffle chambers through which water flows. ... Planted gravel filter/ reed bed. ... Storage tank.
How do you purify sewage water for drinking water?
In secondary treatment, bacteria are added to the wastewater to ingest organic solids, producing secondary sludge that settles to the bottom. Tertiary treatment filters the water to remove whatever solids remain, disinfects it with chlorine, and removes the salt.
What are the 5 steps of wastewater treatment?
Treatment StepsStep 1: Screening and Pumping. ... Step 2: Grit Removal. ... Step 3: Primary Settling. ... Step 4: Aeration / Activated Sludge. ... Step 5: Secondary Settling. ... Step 8: Oxygen Uptake. ... Sludge Treatment.
What are the 7 steps to clean water?
The 7 Steps to Purify WaterScreening. ... Coagulation and Flocculation. ... Sedimentation. ... Filtration. ... Disinfection. ... Corrosion and Scale Control. ... Taste and Odor Control.
How does municipality clean water?
The most common disinfection process used is chlorination. Chlorine comes in many different forms, including chlorine gas (the most common), chlorine dioxide and hypochlorite. Whichever method is used, chlorine is added to the water in a quantity to ensure that most, if not all, viruses and bacteria are destroyed.
What are the steps in water treatment used by community water system?
1.) Screening. Surface water (water from Angat Dam and Ipo Dam) often contains large debris, such as sticks, logs, leaves, fish, and trash. ... 2.) Pre-Chlorination (Disinfection) ... 3.) Rapid Mixing. ... 4.) Flocculation. ... 5.) Coagulation. ... 6.) Sedimentation. ... 7.) Filtration. ... 8.) Disinfection.More items...
What are the steps of water treatment?
Today, the most common steps in water treatment used by community water systems (mainly surface water treatment) include: Coagulation and flocculation are often the first steps in water treatment. Chemicals with a positive charge are added to the water.
Why do people use water treatment units?
Even though EPA regulates and sets standards for public drinking water, many Americans use a home water treatment unit to: Remove specific contaminants. Take extra precautions because a household member has a compromised immune system. Improve the taste of drinking water.
How does a water treatment unit work?
Even though EPA regulates and sets standards for public drinking water, many Americans use a home water treatment unit to: 1 Remove specific contaminants 2 Take extra precautions because a household member has a compromised immune system 3 Improve the taste of drinking water
What is the process of boiled water?
Distillation is a process in which impure water is boiled and the steam is collected and condensed in a separate container, leaving many of the solid contaminants behind. Disinfection. Disinfection is a physical or chemical process in which pathogenic microorganisms are deactivated or killed.
Why is surface water more contaminated than ground water?
Typically, surface water requires more treatment and filtration than ground water because lakes, rivers, and streams contain more sediment and pollutants and are more likely to be contaminated than ground water. Some water supplies may also contain disinfections by-products, inorganic chemicals, organic chemicals, and radionuclides.
What is a water softener?
Water Softeners. A water softener is a device that reduces the hardness of the water. A water softener typically uses sodium or potassium ions to replace calcium and magnesium ions, the ions that create “hardness.”. Distillation Systems.
What is the most common type of water treatment system?
The most common types of household water treatment systems consist of: Filtration Systems. A water filter is a device which removes impurities from water by means of a physical barrier, chemical, and/or biological process. Water Softeners. A water softener is a device that reduces the hardness of the water.
Why Treat Wastewater?
It's a matter of caring for our environment and for our own health. There are a lot of good reasons why keeping our water clean is an important priority:
Wastewater treatment
The major aim of wastewater treatment is to remove as much of the suspended solids as possible before the remaining water, called effluent, is discharged back to the environment. As solid material decays, it uses up oxygen, which is needed by the plants and animals living in the water.
What is water treatment?
The water treatment process to deliver safe and wholesome water to customers includes many steps. Coagulation, flocculation, sedimentation, filtration, and disinfection are the water treatment processes that make up a conventional surface water treatment plant. These water treatment processes ensure that the water consumers receive is safe ...
What is the purpose of the Surface Water Treatment Rule?
The goal of the SWTR is to reduce illnesses related to pathogens in drinking water. These pathogens include coliform, Giardia, and Cryptosporidium .
How do clarifiers work?
The large flocs will settle out of suspension via gravity. Clarifiers can remove a very large percentage of the suspended materials in water. In some plants, clarifiers remove as much as 90% of the suspended solids load. Particles that do not settle will be removed by filtration in the next treatment step.
What is coagulation in water treatment?
History of Coagulation in Drinking Water Treatment. Coagulation has been an important process in high-rate filtration plants in the United States since the 1880s. Aluminum and iron salts have been used in the coagulation process since the beginning. These salts are still the most commonly used coagulants today.
What is turbidity in water?
This cloudiness is known as turbidity . Visual turbidity is unpleasant to consumers. Visual turbidity is also an indicator to operators and regulators that the water may still contain pathogens. The Surface Water Treatment Rule therefore requires that turbidity be removed to very low levels.
What are the common coagulants used today?
Common coagulants used today include aluminum sulphate (alum), ferric sulphate, ferric chloride, and sodium aluminate. Synthetic organic polymers were introduced in the 1960s. Depending on your system’s water quality, it may be necessary to employ a combination of two or more coagulants.
How does contact time work in water treatment?
In order for systems to be sure that they are properly disinfecting the filtered water, the Surface Water Treatment Rule requires systems to provide enough contact time. Contact time (CT) is a function of the known disinfection concentration and the amount of time that the disinfectant is in contact with the water. Contact time is expressed in terms of mg/L-min. The EPA has published tables that show how much CT credit water systems will receive. In order to use these tables you use the concentration of chlorine, time, water temperature and pH.
What is the first step in water treatment?
The steps of water treatment. The first step is usually to add coagulants (Koh-AG-yu-lunts). These are chemicals that cause those solid bits to clump together. Even if those solids didn’t hurt you, they could cloud water and give it a funny taste. By making these bits clump, they become bigger — and easier to remove.
Where does water come from in a town?
Typically, a town will pump it from a river, lake or groundwater aquifer. But this water can host an array of germs and solids — waterborne dirt, rotting plant bits and more. That’s why a community will typically process that water — clean it — through a series of steps before sending on to your faucet.
How does reverse osmosis work?
Reverse osmosis can replace a number of steps in the water treatment process or reduce the number of chemicals added to water.
What happens when the EPA levels are higher than the 15 ppb threshold?
When levels are higher than EPA’s 15 ppb threshold, the government requires that cities take steps to control corrosion and notify the public. Homeowners are unlikely to ever realize they have such a problem with their own well. The researchers reported those findings in 2015 in the Journal of Water and Health.
Where do people get their drinking water from?
Most people get their drinking water from lakes, rivers or groundwater aquifers. But before it flows out the tap, cities will typically treat the water in big industrial plants, as here, to purify it.
Do well owners get their own water?
Well owners are on their own. More than one in every seven U.S. residents gets water from wells and other private sources. These are not regulated by a federal law known as the Safe Drinking Water Act. These people face the same contamination challenges as municipal water systems.
How to clean a water treatment plant?
Among the methods used to clean such plants, dry ice method is the one that makes the clean up faster and less expensive. Waste water treatment plant cleaning includes cleaning of: 1 Filter Presses 2 Clarifiers 3 Tanks 4 Pumps 5 Electric Motors 6 Other Filtration systems
How does waste water get cleaned?
Waste water gets cleaned with the help of huge waste water treatment plants . These plants also need to be cleaned and maintained properly to avoid any kind of pollutants getting dissolved in the clean water. Cleaning waste water is a part of sewage treatment which deals in the cleaning of water especially from household sewage.
What is the purpose of cleaning waste water?
Various chemical, physical and biological processes are used to remove contaminants and generate water that is safe for the environment. Sewage treatment is also known as waste water treatment.
Where is built up sludge found?
While cleaning the waste water, built up sludge is found in pits and wells at treatment plants . This can negatively affect the wastewater treatment process. Various machine combinations are used to clean these pits and wells so that this sludge can be removed over a certain amount of time.
Is waste water harmful?
Waste water contains numerous elements and substances that are harmful. These are removed with the use of treatment plants. Now, these plants are to be cleaned, maintained and emptied frequently to avoid any unwanted spread of diseases. While cleaning the waste water, built up sludge is found in pits and wells at treatment plants.
Why upgrade wastewater treatment system?
Enhanced treatment systems enable some wastewater plants to produce discharges that contain less nitrogen than plants using conventional treatment methods . Upgrading wastewater treatment systems is often expensive for municipalities and rate payers, but upgrades can pay for themselves or end up saving a plant money.
How to maintain a septic system?
Homeowners are responsible for maintaining their septic systems in most cases. To protect and maintain their system, homeowners should: 1 Have their system inspected regularly and pump their tank as necessary 2 Use water efficiently 3 Not dispose of household hazardous waste in sinks or toilets 4 Avoid driving vehicles or placing heavy objects on their drainfield 5 Visit EPA's decentralized wastewater (septic) systems webpage to learn more about septic systems and EPA's SepticSmart Week Program 6 Consult EPA's guide on maintaining septic systems for more information: Homeowner's Guide to Septic Systems (PDF) (9 pp, 3 MB, About PDF)
What is the source of nitrogen and phosphorus in wastewater?
Wastewater contains nitrogen and phosphorus from human waste, food and certain soaps and detergents. Once the water is cleaned to standards set and monitored by state and federal officials, it is typically released into a local water body, where it can become a source of nitrogen and phosphorus pollution. Some wastewater treatment plants are able ...
How does a septic system contribute to nutrient pollution?
Septic systems can easily become a source of nutrient pollution if not properly maintained. Most homes and businesses send their wastewater to a treatment plant where many pollutants are removed from the water. Wastewater treatment facilities in the United States process approximately 34 billion gallons of wastewater every day.
What percentage of homes in the US have septic systems?
Septic Systems. Approximately 20 percent of homes in the United States use septic systems that locally treat their wastewater. When a septic system is improperly managed, elevated nitrogen and phosphorus levels can be released into local water bodies or ground water.
Who is responsible for septic system maintenance?
Homeowners are responsible for maintaining their septic systems in most cases. To protect and maintain their system, homeowners should: Have their system inspected regularly and pump their tank as necessary. Use water efficiently. Not dispose of household hazardous waste in sinks or toilets.
What causes a septic system to fail?
Common causes of septic system failure include aging infrastructure, inappropriate design, overloading with too much wastewater in too short a period of time and poor maintenance.

Coagulation
Flocculation
- Once water has been treated with the coagulation chemicals it enters a tank with giant paddles. These mix the chemicals and water together and enable the micro particles to form into larger pieces that are likely to stick together, making the sedimentation process in water treatmentmore effective. This process is known as flocculation.
Sedimentation
- Once the flocculation process is complete the water enters the sedimentation phase. Once the water is in the primary settling basins the large particles formed during the coagulation and flocculation stage separate and settle. This leaves cleaner water for further processing in the treatment plant. The solids form a sludge layer which forms on the bottom of the tank and is late…
Ph Adjustment
- After the disinfection phase the water undergoes a pH treatment stage. Lime or calcium oxide makes water less acidic by adjusting the pH. It is also less corrosive to domestic water pipes. Polyphosphate solution is also added to the water at this stage to keep the lime dissolved.
Fluoridation
- Once water exits the sedimentation basins, fluorosilicic acid is added in small quantities. This helps fluoridate the water supply to help in the prevention of dental decay.
Filtration
- Finally, water goes through a filtration process using rapid gravity filters. Sand is commonly used in this type of filter and it removes any further sediment or particles in the water. During this final stage water is passed through a filter in a regulated manner. Any particles stick to the filter, leaving clean water to be piped into the municipal supply. Pumping stations pump water to dom…
Coagulation
Flocculation
Sedimentation
Filtration
Disinfection
- After the water has been filtered, water treatment plants may add one or more chemical disinfectants (such as chlorine, chloramine, or chlorine dioxide) to kill any remaining parasites, bacteria, or viruses. To help keep water safe as it travels to homes and businesses, water treatment plants will make sure the water has low levels of the chemical ...
Chlorination Operations
Conclusion
- Following the coagulant chemical addition and the rapid mix processes, the raw water will continue on to a flocculation basin. The goal of the flocculation treatment process is to increase the size of the flocs in order to increase their ability to settle out.